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// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use std::task;
use std::rand::{task_rng, Rng};
static MAX_LEN: uint = 20;
static mut drop_counts: [uint, .. MAX_LEN] = [0, .. MAX_LEN];
static mut clone_count: uint = 0;
#[deriving(Rand, PartialEq, PartialOrd, TotalEq, TotalOrd)]
struct DropCounter { x: uint, clone_num: uint }
impl Clone for DropCounter {
fn clone(&self) -> DropCounter {
let num = unsafe { clone_count };
unsafe { clone_count += 1; }
DropCounter {
x: self.x,
clone_num: num
}
}
}
impl Drop for DropCounter {
fn drop(&mut self) {
unsafe {
// Rand creates some with arbitrary clone_nums
if self.clone_num < MAX_LEN {
drop_counts[self.clone_num] += 1;
}
}
}
}
pub fn main() {
// len can't go above 64.
for len in range(2u, MAX_LEN) {
for _ in range(0, 10) {
let main = task_rng().gen_iter::<DropCounter>()
.take(len)
.collect::<Vec<DropCounter>>();
// work out the total number of comparisons required to sort
// this array...
let mut count = 0;
main.clone().as_mut_slice().sort_by(|a, b| { count += 1; a.cmp(b) });
// ... and then fail on each and every single one.
for fail_countdown in range(0, count) {
// refresh the counters.
unsafe {
drop_counts = [0, .. MAX_LEN];
clone_count = 0;
}
let v = main.clone();
task::try(proc() {
let mut v = v;
let mut fail_countdown = fail_countdown;
v.as_mut_slice().sort_by(|a, b| {
if fail_countdown == 0 {
fail!()
}
fail_countdown -= 1;
a.cmp(b)
})
});
// check that the number of things dropped is exactly
// what we expect (i.e. the contents of `v`).
unsafe {
for (i, &c) in drop_counts.iter().enumerate() {
let expected = if i < len {1} else {0};
assert!(c == expected,
"found drop count == {} for i == {}, len == {}",
c, i, len);
}
}
}
}
}
}
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